Thermal spray coating for seamless and radio-transparent electronic device housing

ABSTRACT

Electronic devices and other apparatuses adapted to receive electromagnetic wave communications are disclosed. An outer housing encloses various device components, including at least an internal antenna located fully therewithin and adapted to receive/send communications from/to an outside source via RF or other electromagnetic waves. A ceramic coating can be a thermal spray coating that covers at least a portion of the outer surface proximate to the internal antenna, and can be “RF transparent”—adapted to allow communications to/from the internal antenna via electromagnetic waves. The outer housing can be plastic, metal or a combination thereof. For metal or other non-RF transparent housings, an RF-transparent insert can be fitted into a window in the housing to permit communications to the internal antenna. The ceramic coating covers some or all of the metal, plastic and/or insert that comprise the outer housing and surface for a final aesthetic finish to the device.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.12/343,335, filed Dec. 23, 2008, and entitled “THERMAL SPRAY COATING FORSEAMLESS AND RADIO-TRANSPARENT ELECTRONIC DEVICE HOUSING,” and whichclaims priority to U.S. Provisional Patent Application No. 61/108,460,filed Oct. 24, 2008, and entitled “THERMAL SPRAY COATING FOR SEAMLESSAND RADIO-TRANSPARENT ELECTRONIC DEVICE HOUSING,” which is incorporatedherein by reference in its entirety and for all purposes.

TECHNICAL FIELD

The present invention relates generally to portable computing devices,and more particularly to the formation of outer housings for suchportable computing or other personal devices.

BACKGROUND

Portable computing devices, such as media players, cellular telephones,PDAs and the like, are becoming omnipresent. With a multitude ofmanufacturers competing for sales of these devices in retail markets,the need to provide state of the art features and content on a devicethat very aesthetically pleasing is increasing. This is particularlytrue given the nature of consumers to desire portable computing devicesthat are “hip” or “cool” looking, with many purchasing decisions forsuch devices being affected by this particular desire. Accordingly, theouter look or feel of a portable computing device can be a criticalfactor in device design.

One design challenge associated with portable computing devices is thecomposition and appearance of the outer housing or enclosure that isused to house the various internal components of the portable computingdevice. A seamless, smooth and/or sleek look is often highly desired,with metal or other similar materials being preferable. Some solutionsto these issues have involved the use of an outer housing that istubular in nature. Various examples of and methods of manufacturing suchtubular outer housings can be found in, for example, commonly owned U.S.patent application Ser. Nos. 10/884,172 and 11/501,184, filed on Jul. 2,2004, and Oct. 7, 2006 respectively, both of which are entitled“HANDHELD COMPUTING DEVICE,” and both of which are incorporated byreference herein in their entireties and for all purposes. Such outerhousings can be used on, for example the iPod® media player or iPhone®cellular telephone made by Apple Inc., among other suitable portablecomputing devices or items.

One drawback to a common approach of manufacturing a generally metallicouter housing for a portable computing device is that metal can be apoor material choice where electromagnetic wave transmissions throughthe material are desired. For example, a cellular telephone thatrequires radio frequency transmissions to operate must either have anexternal antenna or a region in the housing through which radio wavescan pass. As a more detailed example, because no external antenna wasused on the iPhone® 2G cellular telephone made by Apple Inc., itsmetallic outer housing included a plastic portion located proximate toan internal antenna or receiver region. This design permitted most ofthe outer housing to be aluminum, but also required a smaller region ofplastic to allow for radio frequency communications through the outerhousing.

Unfortunately, the use of two different materials for the outer housingresults in a seam between the materials, as well as the likelihood of atwo-toned look in the overall look of the device. One solution to avoidsuch seams and two-toned appearances can be to use an outer housing thatis comprised entirely of a “radio transparent” material, such as a hardplastic. One drawback to this approach, however, is that metallicsurface finishes are thought by some to be more aesthetically pleasingthan plastic surface finishes. In general, metallic surface finisheshave a look and feel that tends to be harder, smoother and sleeker thanplastic surface finishes. Thus, with respect to a portable electronicdevice that must be able to communicate via electromagnetic waves, adesigner has traditionally needed to choose at least one of the lesseraesthetically pleasing alternatives involving an external antenna, aseam or seams on the outer housing, or an outer housing made entirely ofplastic or some other radio transparent material.

While many designs and methods of manufacture for providing outerhousings on portable computing devices and other similar items havegenerally worked well in the past, there is always a desire to providenew and improved designs that result in aesthetically pleasing andfunctional outer housings for such portable computing devices. Inparticular, it is desirable to provide a portable computing device thatcan communicate via electromagnetic waves, have an internal antenna,have no seams in the outer housing, and have an outer housing with asleek and hard finish that is metallic or similar thereto.

SUMMARY

It is an advantage of the present invention to provide an aestheticallypleasing outer housing for a portable computing device, such as acellular telephone or media player. Such an outer housing should beusable for a portable computing device adapted to communicate viaelectromagnetic waves, have an internal antenna, have no seams in theouter housing, and have an outer housing with a sleek and hard finishthat is metallic or similar thereto. This can be accomplished at leastin part through the use of a ceramic thermal spray coating that isapplied to the outer surface or surfaces of one or more outer housingcomponents of the computing device.

In various embodiments, the invention can include an electronic devicehaving an outer housing configured to enclose at least a portion of theelectronic device and having an outer surface, an internal antennalocated fully within the outer housing, said receiver being adapted toreceive communications from an outside source via electromagnetic waves,and a ceramic coating that covers at least a portion of the outersurface proximate the internal antenna, wherein the ceramic coating isadapted to allow communications to the internal antenna viaelectromagnetic waves.

In various detailed embodiments, a portable, handheld, personalcomputing device is provided. This device can include a plurality ofinternal operational components adapted to provide processing for a userthereof, a metal outer housing configured to enclose at least a portionof the internal operational components, said metal outer housing havinga first outer surface and an opening therethrough, an internal antennalocated fully within the metal outer housing, said internal antennabeing adapted to receive communications from an outside source via radiofrequency waves, a processor located within the metal outer housing andcoupled to the internal antenna, said processor being adapted to providean output for a user as a result of communications from an outsidesource, an insert fitted within the opening in the metal outer housingsuch that a seam between the metal outer housing and the insert isformed, said insert being transparent to radio frequency waves andhaving a second outer surface, and a ceramic coating that covers thefirst outer surface and second outer surface such that the seam ishidden thereby, wherein said ceramic coating is also transparent toradio frequency waves.

In various embodiments, a radio transparent ceramic coating can beapplied using a thermal spray process. This allows for the use of aplastic or other radio transparent material, such that an internalantenna can be used, and also results in a hard and sleek ceramic finishfor the outer housing. Any seam or seams between different outer housingcomponents can be covered by the thermal spray ceramic material toprovide a final seamless ceramic look and finish.

Other apparatuses, methods, features and advantages of the inventionwill be or will become apparent to one with skill in the art uponexamination of the following figures and detailed description. It isintended that all such additional systems, methods, features andadvantages be included within this description, be within the scope ofthe invention, and be protected by the accompanying claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The included drawings are for illustrative purposes and serve only toprovide examples of possible structures and arrangements for thedisclosed inventive apparatus and method for providing an outer housingfor a personal computing device by using a thermal spray coating. Thesedrawings in no way limit any changes in form and detail that may be madeto the invention by one skilled in the art without departing from thespirit and scope of the invention.

FIG. 1A illustrates in back plan view the obverse side of an exemplarycellular telephone having a metal and plastic housing and a two-tonedoverall appearance.

FIG. 1B illustrates in back plan view the obverse side of an alternativeexemplary cellular telephone having a fully plastic outer housing and auniform overall appearance.

FIG. 2A illustrates in partial top cross-sectional view an exemplarycellular telephone having an internal antenna and a metal housing.

FIG. 2B illustrates in partial top cross-sectional view an alternativeexemplary cellular telephone having an internal antenna a metal andplastic housing.

FIG. 2C illustrates in partial top cross-sectional view anotheralternative exemplary cellular telephone having an internal antenna anda fully plastic or glass housing.

FIG. 3 illustrates in partial top cross-sectional view an exemplarycellular telephone having an internal antenna, a fully plastic housingand a thermal spray coating, according to one embodiment of the presentinvention.

FIG. 4 illustrates in partial top cross-sectional view an alternativeexemplary cellular telephone having an internal antenna, a metal andplastic housing and a thermal spray coating, according to anotherembodiment of the present invention.

FIG. 5 illustrates in cross-sectional view an exemplary thermal sprayprocess and various aspects thereof.

DETAILED DESCRIPTION

Exemplary applications of apparatuses and methods according to thepresent invention are described in this section. These examples arebeing provided solely to add context and aid in the understanding of theinvention. It will thus be apparent to one skilled in the art that thepresent invention may be practiced without some or all of these specificdetails. In other instances, well known process steps have not beendescribed in detail in order to avoid unnecessarily obscuring thepresent invention. Other applications are possible, such that thefollowing examples should not be taken as limiting.

In the following detailed description, references are made to theaccompanying drawings, which form a part of the description and in whichare shown, by way of illustration, specific embodiments of the presentinvention. Although these embodiments are described in sufficient detailto enable one skilled in the art to practice the invention, it isunderstood that these examples are not limiting; such that otherembodiments may be used, and changes may be made without departing fromthe spirit and scope of the invention.

The invention relates in various embodiments to aesthetically pleasingouter housings for a portable personal computing device, such as aniPod® media player or iPhone® cellular telephone made by Apple Inc.,among other suitable devices or items. Such outer housings can begenerally tubular and handheld in nature, although the exact shape andsize can vary. In addition, such outer housings are preferably adaptedto allow for the transmission of electromagnetic waves, such that radiofrequency (“RF”) communications and other transmissions can be madethrough the outer housing. Further, these outer housings are preferablyseamless, sleek and sufficiently hardened in look and feel.

In various embodiments of the present invention, an outer housing for aportable personal computing device is provided. Various embodiments mayalso include or relate to the entire portable personal computing device.The outer housing can be adapted to surround and protect a plurality ofinternal operational components for the computing device. The outerhousing can include a single base component or a plurality of componentsassembled together to form a uniform outer housing. The one or more basecomponents forming the outer housing can then be coated with a thermallysprayed material that is radio transparent, such as a ceramic. Thethermally sprayed ceramic or other material can cover any seams betweenouter housing components, such that the device has a uniform, seamless,sleek and hardened finish that allows for radio communications with aninternal antenna.

Although it is contemplated that the internal antenna for use with thepresent invention be fully or completely internal, other arrangementsmay also be used. For example, a mostly internal but partially externalantenna may be used. Further, an extendable antenna that can be at leastpartially external in one position and fully internal in anotherposition may also be used. This could result in the user having anoption to extend an antenna if desired, while still providing goodantenna service and reception in a fully internal position. Otheralternative internal, external and combination antenna arrangements maybe used, and the present invention is contemplated to be used withrespect to any and all such arrangements.

Referring first to FIG. 1A, the obverse side of an exemplary cellulartelephone having a metal and plastic housing and a two-toned overallappearance is illustrated in back plan view. As shown, cellulartelephone 10 has a back surface housing having an aluminum component 11and a plastic component 12, with the plastic component being locatedproximate to an internal antenna 13, such that RF transmissions can bemade through the plastic component to the antenna. Because two differentmaterials are used, a seam 14 exists between these metal and plastichousing components. As noted above, such a seam and two-toned appearancemight be less aesthetically pleasing to some that a uniform outerhousing.

Moving next to FIG. 1B, the obverse side of an alternative exemplarycellular telephone having a fully plastic outer housing and a uniformoverall appearance is shown in back plan view. Cellular telephone 20 hasa uniform plastic outer housing 21, such that RF transmissions can bemade therethrough in all locations. However, as noted above, plasticfinishes may be less aesthetically pleasing to some than metallic orsimilar finishes. Although the location of an internal antenna can be inthe same general area as that which is shown in FIG. 1A, it will beappreciated such an internal antenna can be in virtually any otherinternal location, since the use of an “RF transparent” plastic for theentire housing provides flexibility in at least this regard.

Continuing to FIG. 2A-2C, various exemplary portable computing devicesare depicted. In FIG. 2A, an exemplary cellular telephone having aninternal antenna and a metal housing is shown in partial topcross-sectional view. As shown, the X notations indicate that noelectromagnetic wave signal can be read by the antenna from a particularlocation. As would be expected, metal housing 11 generally does notallow for RF transmissions therethrough with respect to internal antenna13. As such, the exemplary arrangement shown in FIG. 2A is generallyimpractical without the use of an external antenna or some RFtransparent window in metal housing 11. The illustrated cross-sectionwould be appropriate to show what happens in locations where there is noRF transparent window in a device housing, such as at the upper portionsof cellular telephone 10 shown in FIG. 1A.

FIG. 2B illustrates in partial top cross-sectional view an alternativeexemplary cellular telephone having an internal antenna within a metaland plastic housing. As shown, the X notations indicate that noelectromagnetic wave signal can be read by the antenna from a particularlocation, but the O notations indicate that an electromagnetic wavesignal from an outside source can be read by the internal antenna. Thisarrangement generally corresponds to that which is shown at the bottomportion of cellular telephone 10 in FIG. 1A, in that RF transmissions tothe internal antenna 13 can be made through an RF transparent plasticportion 12 of the outer housing, but not through the metal portion 11 ofthe outer housing. As such, it is preferable that the internal antenna13 be located proximate to the plastic portion 12 or other RFtransparent region of the device.

FIG. 2C illustrates in partial top cross-sectional view anotheralternative exemplary cellular telephone having an internal antenna anda fully plastic or glass housing. This alternative arrangement generallycorresponds to that which is shown in FIG. 1B, in that RF transmissionsto the internal antenna 13 can be made through the entire plastic outerhousing 21. As will be appreciated, there can be various drawbackseither functionally or aesthetically with respect to each of theembodiments shown in FIGS. 2A-2C. In general, all of these drawbacks areovercome in the various inventive embodiments disclosed and describedherein.

Turning now to FIG. 3, an exemplary cellular telephone having aninternal antenna, a fully plastic, glass or other RF transparent housingand a thermal spray coating is shown in partial top cross-sectionalview, according to one embodiment of the present invention. Cellulartelephone 100 has a fully internal antenna 113, with such a fullyinternal antenna being located entirely within the outer housing of thedevice. Although no antenna component is located outside the outerhousing, it will appreciated that some embodiments may include such anelement, as noted above. A plastic outer housing component 121 can fullyor substantially house the entire cellular telephone 100, similar to theplastic outer housing 21 of FIGS. 1B and 2C. In addition, a thermalspray coating 130 is applied to the outer surface of plastic housing121. This thermal spray coating can be a material that is radio (i.e.,RF) transparent, such as ceramic, such that RF communications from anoutside source can transmit through both the coating and plastic housingto reach the internal antenna. In some embodiments, the coating cancover all or substantially all of the plastic housing, such that auniform and seamless surface is provided. Such a surface can besmoother, stiffer, harder, consistent and continuous than typicalplastic materials, resulting in a more aesthetically pleasing outerappearance of the device.

FIG. 4 illustrates in partial top cross-sectional view an alternativeexemplary cellular telephone having an internal antenna, a metal andplastic housing and a thermal spray coating, according to anotherembodiment of the present invention. Cellular telephone 200 can have abase outer housing component 211 made of metal, with such a metalhousing component having one or more “windows” or openings therein. Oneor more inserts or other outer housing components 212 can fit into thesewindows or openings, preferably such that the surfaces are flush tocreate a mostly smooth and continuous outer surface. Such an insert orother housing component 212 can be an radio transparent material, suchas plastic or glass, and can be placed proximate to an internal antenna213, such that RF transmissions can be made from an outside source,through the insert 212 and to the internal antenna 213.

Such an arrangement is generally similar to that which is shown anddescribed with respect to FIG. 1A above, with the aluminum and plasticouter housing components necessarily forming a seam between the two.Unlike the foregoing example, however, cellular telephone 200 also has athermal spray coating 230 applied to the outer surfaces of both themetal housing component 211 and the radio transparent insert or housingcomponent 212. Again, this thermal spray coating 230 can be a ceramic orother material that is radio transparent, such that RF communicationscan be made between an outside location and an internal antenna locatedentirely within the outer housing of the device. Advantageously,applying the thermal spray coating 230 results in a thin layer thatcovers the metal outer housing component 211, the plastic or glassinsert or housing component 212, and any seams between the two. In someembodiments, the coating can cover all or substantially all of the metaland plastic housing components, such that a uniform and seamless outersurface is provided. As in the above embodiment, such a surface can besmoother, stiffer and harder than typical plastic materials, resultingin a more aesthetically pleasing outer appearance of the device whilestill permitting for RF communications. Such a finish is thus moreconsistent and continuous than that resulting from typical combinationsof metal and plastic materials, resulting in a more aestheticallypleasing outer appearance of the device.

FIG. 5 illustrates in cross-sectional view an exemplary thermal sprayprocess and various aspects thereof. A thermal spray process generallyinvolves melting or otherwise breaking down a coating material into afine powder that is then sprayed onto a surface using a plasma spraygun, a cross-section of which is illustrated. In general, a plasma spraygun 1 can include a negatively charged component 2 and a positivelycharged component 3 inside a housing 4 having an opening 5 for theejection of thermal spray material 6. This thermal spray material can besprayed onto an outside device 10, which results in the formation of athermal spray coating 9 on the device.

Various materials can be used in such a thermal spray process, includingmetals, ceramics and cermets. Because metals and cermets tend to be poortransmitters for RF communications, it is preferable that the thermallysprayed material for use with the present invention be a ceramic powdermaterial. Such a ceramic can be, for example, an aluminum based powder,a chromium oxide based powder, a titania based powder or a zirconiumoxide based powder, among other suitable materials.

The ceramic thermal spray process contemplated for use with the presentinvention can be that which is provided by any number of vendors, suchas, for example, Sulzer Metco of Westbury, N.Y.; Tocalo Co., Ltd. ofKobe-shi, Japan; or Plasma Giken Koygo, Co. Ltd., of Tokyo, Japan. Othervendors may also be used for this process, as may be applicable. Ingeneral, any suitable thermal spray process that involves the use of aplasma spray gun or other similar device to effectively “paint” or coata thin layer onto a surface can be used with the present invention. Inparticular, such a layer should be a ceramic or other radio transparentmaterial.

Although many typical thermal spray processes use powders havinggranules on the order of 100 microns in diameter, it is though thatgranules of this size may be too large for an aesthetically pleasingsmooth surface finish on a portable computing device, as described indetail above. As such, it is contemplated that a thermal spray processusing smaller granule sizes can be used with for the present invention.For example, a fine powder thermal spray can be used having granulesthat are about 10 or even 5 microns in diameter, on average. This canresult in a smoother surface finish on the final product.

In some embodiments, particularly where granules of a larger diameterare used in the thermal spray process, a finishing step might beemployed to polish or otherwise smooth out the outer surface of thethermal spray layer after it has been applied to the outer surface(s) ofthe outer housing component(s). For example, a diamond powder sandingprocess might be used to polish or smooth out the final outer surface.Such a final finishing step can improve the overall look of the portablecomputing device to be as aesthetically pleasing as possible.

Although the foregoing invention has been described in detail by way ofillustration and example for purposes of clarity and understanding, itwill be recognized that the above described invention may be embodied innumerous other specific variations and embodiments without departingfrom the spirit or essential characteristics of the invention. Certainchanges and modifications may be practiced, and it is understood thatthe invention is not to be limited by the foregoing details, but ratheris to be defined by the scope of the appended claims.

What is claimed is:
 1. A method of forming a portable, handheld,personal computing device, comprising: providing a first outer housingportion configured to enclose at least a portion of a plurality ofinternal operational components, the first outer housing portion havinga first outer surface; placing an internal antenna within the firstouter housing portion, the internal antenna being adapted to receivecommunications from an outside source via radio frequency waves;combining a second outer housing portion with the first outer housingportion such that a seam between the first and second outer housingportions is formed, the second outer housing portion being transparentto radio frequency waves and having a second outer surface; andprotecting the first and seond outer housing portions by thermallyspraying a ceramic coating on at least a portion of the first outersurface and at least a portion of the second outer surface, wherein theseam is hidden by the thermally sprayed ceramic coating, wherein thethermally sprayed ceramic coating is comprised of uniform radiofrequency transparent material to allow passage of radio frequencycommunications to and/or from the internal antenna.
 2. A method asrecited in claim 1, wherein the portable computing device comprises acellular telephone.
 3. A method as recited in claim 1, wherein theceramic coating comprises a fine powder thermal spray having granulesthat are primarily about 5 microns or less in diameter and the ceramiccoating provides a smooth and consistent finish for the portable,handheld, personal computing device.
 4. A method as recited in claim 1,wherein the ceramic coating covers substantially all of the first andsecond outer surfaces.
 5. A method as recited in claim 1, wherein thesecond outer housing portion is plastic.
 6. A method as recited in claim1, wherein the first outer housing portion is aluminum.
 7. A method asrecited in claim 1, wherein the ceramic coating provides a continuousand unbroken finish across the portable, handheld, personal computingdevice.
 8. A method as recited in claim 1, wherein a plasma gun is usedfor the thermal spraying.
 9. An electronic device, comprising: a housingconfigured to house an internal antenna adapted to communicate via radiofrequency waves, the housing comprising a first portion having a firstsurface and a second portion having a second surface adjacent the firstsurface at a junction region, wherein at least one of the first portionand second portion is transparent to radio frequency waves; and athermally sprayed ceramic coating disposed on at least a portion of thefirst surface and at least a portion of the second surface over at leastthe junction region such that the junction region is not visible throughthe thermally sprayed ceramic coating, wherein the thermally sprayedceramic coating is comprised of uniform radio frequency transparentmaterial allowing passage of radio frequency communication of theinternal antenna therethrough.
 10. The electronic device of claim 9,wherein the thermally sprayed ceramic coating provides a consistentfinish over the junction region.
 11. The electronic device of claim 9,wherein the internal antenna is located fully within the housing. 12.The electronic device of claim 9, wherein at least one of the firstportion and the second portion comprises a plastic material.
 13. Theelectronic device of claim 9, further comprising a processor locatedwithin the housing, the processor adapted to communicate with theinternal antenna.
 14. The electronic device of claim 9, wherein theelectronic device comprises a handheld electronic device.
 15. Theelectronic device of claim 14, wherein the handheld electronic device isa mobile telephone.
 16. The electronic device of claim 9, wherein thethermally sprayed ceramic coating is substantially free of metal.
 17. Ahousing for an electronic device, the housing comprising: a firstportion configured to house an internal antenna adapted to communicatevia radio frequency waves, the first portion comprising a first surface;a second portion comprising a second surface, wherein the second surfaceis positioned adjacent the first surface at a junction region, whereinat least one of the first portion and second portion is transparent toradio frequency waves; and a thermally sprayed ceramic coating disposedon at least a portion of the first surface and at least a portion of thesecond surface over at least the junction region such that the junctionregion is not visible through the thermally sprayed ceramic coating,wherein the thermally sprayed ceramic coating is comprised of uniformradio frequency transparent material allowing passage of radio frequencycommunication of the internal antenna therethrough.
 18. The housing ofclaim 17, wherein the thermally sprayed ceramic coating comprises aceramic powder.
 19. The housing of claim 18, wherein the thermallysprayed ceramic coating is selected from a group comprising: an aluminumbased powder, a chromium oxide based powder, a titania based powder, anda zirconium oxide based powder.
 20. The housing of claim 17, wherein theinternal antenna is located fully within the housing.
 21. The housing ofclaim 17, wherein at least one of the first portion and the secondportion comprises a plastic material.
 22. The housing of claim 17,wherein at least one of the first portion and the second portioncomprises a glass material.
 23. The housing of claim 17, wherein atleast one of the first portion and the second portion comprises a metalmaterial.
 24. The housing of claim 23, wherein the metal material is analuminum material.
 25. The housing of claim 17, wherein the thermallysprayed ceramic coating provides a consistent finish over the junctionregion.